1. Field of the Invention
This invention relates generally to compositions, methods and apparatus for use in the manufacture of semiconductor, photovoltaic, LCD-TFT, or flat panel type devices. More specifically, the invention relates to methods of forming a thin film on a substrate.
2. Background of the Invention
One reason the requirements for suitable metallorganic precursors, used in chemical vapor depositions (CVD) and/or atomic layer depositions (ALD) for semiconductor manufacturing processes, are increasing is due to the high surface coverage required by the deposited films, as compared to that found through physical vapor deposition methods (e.g. PVD, sputtering method).
For example, preferred production methods for GeSbTe alloy thin films, which are used in phase change memory devices, are changing from PVD methods to CVD/ALD methods with the increasing the capacity of memory cell. The demonstration sample of 512 Mega-bit PRAM was made by PVD method under 90 nm technology node processes in 2007, however in the future CVD/ALD methods will likely be necessary for the production of giga-bit scale (and greater) PRAM devices. A main issue for these future production methods is identifying suitable precursors which will allow for a low temperature, low impurity CVD/ALD film deposition. Similar situations are seen in many stages of semiconductor device manufacture. For instance, precursors for deposition of metallic titanium films are needed, due to the high level of impurities observed in the current processes.
Consequently, there exists a need for a need for materials and methods to deposit precursors to form thin films in semiconductor manufacturing processes.